Leftover Prime Rib Beef Stroganoff – Lucious roasted prime rib gives this stroganoff recipe deep, rich flavor. Uncooked chuck roast, London broil or top sirloin may be substituted, but leftover prime rib makes this recipe special. – olive oil, leftover prime rib, yellow onion (diced small), mushrooms (washed and quartered), fresh garlic (diced finely), Cognac,…